Within the context of the present invention hearing devices for instance comprise hearing aids, such as behind-the-ear (BTE), in-the-ear (ITE) or completely-in-canal (CIC) hearing aids, earphones, hearing protection devices, as well as ear-level communication, noise reduction and sound enhancement devices. Hearing aids (also commonly referred to as hearing instruments or hearing prostheses) are specifically utilised by persons having a hearing impairment, in order to compensate their hearing loss and improve their hearing ability as much as possible to the level of a person with normal hearing.
A frequent complaint of users of hearing devices, especially when they start wearing them for the first time, is that the sound of their own voice is too loud or that it sounds like they are talking into a barrel. This so-called “occlusion effect” occurs when an object fills the outer portion of a person's ear canal (commonly also referred to as the auditory canal) and is especially pronounced when the ear canal is sealed, e.g. by an otoplastic. It is caused by bone-conducted sound vibrations reverberating off the object filling the ear canal. The occlusion effect can be reduced by employing large vents. However, large vents give rise to increased acoustic feedback, so the amount of amplification that is applied by a hearing device must be limited in order to avoid it generating unpleasant whistling and squealing sounds. Alternatively, methods exist for actively reducing occlusion such as described in EP 2 104 376 A2. Hereby, sound in the auditory canal is picked up by a microphone and the microphone signal is applied to a filter. The filtered microphone signal is fed back to an input of a receiver which is used to emit the sound into the auditory canal. At least part of a transducer transmission function, which is defined for the transmission path from the input of the receiver via the auditory canal to the output of the microphone, is measured and the filter can for instance be adjusted as a function thereof. Typically, a filter which is assumed to have optimal characteristics is selected during the process of hearing device fitting, i.e. adjusting the hearing device settings to the needs of the user, by a hearing device professional such as a hearing device acoustician based on a variety of criteria. A very important criterion is the user's subjective perception of his/her own voice. However, the user generally requires time to get used to a new hearing device and therefore the settings must be fine-tuned after a certain time period of using the hearing device especially in real life listening situations. Therefore, frequently the user will have to return to the hearing device professional multiple times in order to readjust and improve the settings of the hearing device.